Bioeconomy Science Institute Maiangi Taiao scientists had achieved a world-first breakthrough — a successful cocksfoot–ryegrass cross capable of producing fertile seed.
Hybrid plants were now growing in a Palmerston North greenhouse — the first time the notoriously difficult pairing has ever produced viable seed, despite decades of international effort.
Bioeconomy Science Institute scientist Wajid Hussain said the result would not change pastures overnight, but it could eventually open new pathways to grasses being more resilient, more nutritious, and better suited to a changing climate.
Cocksfoot and ryegrass were two foundational species in New Zealand agriculture. Cocksfoot offered drought tolerance and persistence; ryegrass provides high feed quality and ease of establishment.
For years, breeders have tried to combine their strengths, but the two species were so distantly related that traditional hybridisation repeatedly failed.
Although Japanese and German researchers in the 1990s managed to produce some plants, nearly 4000 previous attempts resulted in hybrids that were weak, infertile, and unable to produce viable seed. The prevailing scientific view became that the barrier was simply too high to overcome without a much deeper understanding of the biology involved.
That deeper understanding came from Dr Hussain, who drew on years of experience working on complex clover crosses. By applying new strategies to navigate the long-standing biological barriers, the team achieved what earlier generations of scientists could not.
The breakthrough came late last year.
"This has been an incredibly risky and technically challenging process but immensely satisfying for the large number of people involved," Dr Hussain said.
"We now have enough of the hybrids to show the method works and to open the door to the next wave of scientific exploration."
When cocksfoot and ryegrass were crossed, an embryo might form, but the seed’s endosperm — the natural food source -— does not. Without that nourishment, the embryo cannot survive.
Before that could happen, the team delicately removed the tiny embryo and transferred it on to an artificial nutrient medium, effectively placing it into a controlled, plant scale equivalent of neonatal intensive care. With this support, the embryo developed into a viable plant and later produced fertile seed.
Bioeconomy Science Institute plant genetics science team leader Marty Faville said good science required careful validation, multiple generations of refinement, and ongoing collaboration with farmers and breeders "but this is an exciting development and a career highlight for many in the team".
Even at this early stage, the achievement was generating interest from pastoral farmers and international research groups, Dr Faville said.
Future development would be supported by Grasslanz Technology, which would explore commercial pathways to help ensure the science ultimately delivers benefits on farm.
For agriculture, any advance with the potential to combine improved feed quality and stronger tolerance to climatic stress was worth attention.
However, researchers were quick to temper expectations.
These plants were a proof of concept, not a commercial product. The hybrid’s traits were not yet optimised for paddock conditions, and further study was needed to understand how best to harness the advantages of combining two species which had never successfully hybridised in nature.
Work would now shift to stabilising fertility, assessing agronomic traits, and developing later generation hybrids, including a planned three-species grass hybrid.
If successful, the research could produce prebreeding material for commercial seed companies in the future but the pathway from breakthrough to farm gate would take time.
For science, the breakthrough opened a door long believed to be locked, Dr Faville said. — Allied Media
